This invention relates to a monolithic integrated circuit device including an AC negative feedback type high frequency amplifier circuit.
In recent years, the amount of informations to be transmitted has increased greatly so that how much informations can be sent presents a serious problem. To solve this problem, a plurality of channels have been provided by increasing the transmission frequency or by increasing the capacity of a repeater.
With recent advance of circuit technology, monolithic integrated circuit has become important in view of economy, miniaturization and high reliability. Recent research is concentrated to combine the monolithic integrated circuit technique with a technique of transmitting a large quantity of informations by increasing the transmission frequency for miniaturizing the circuit while utilizing a number of channels in such high frequency band as several hundreds MHz. This resulted in various new techniques.
However, when the circuit device is fabricated with the monolithic integrated circuit technique, it is extremely difficult to manufacture, at a high yield, devices having predetermined characteristic by preparing circuit element having predetermined values as in the prior art in which the circuit device is fabricated with discrete component elements. Especially, when a device utilized in such high frequency band as several hundreds MHz is fabricated with a monolithic integrated circuit, dimensional errors of various component elements of the device, nonuniformity of the semiconductor material utilized to form the device and a small misalignment of the mask have a great influence upon the characteristics of the completed device. Especially, in an amplifier circuit utilized in a high frequency band higher than several hundreds MHz, nonuniformities described above greatly affect the frequency characteristic, thus decreasing the yield of satisfactory products.
Although various efforts have been made for solving the problems described above encountered when a high freqeuncy amplifier circuit is prepared with monolithic integrated circuit technique, satisfactory high yeild was not obtained which increases the cost of each device and makes it difficult to prepare it with mass production process.